Total Recall just got real: Researchers genetically erase bad memories

Anyone who's watched Total Recall—the 1990 scifi classic or its 2012 mediocre remake—knows how this goes down: By selectively replacing a person's memories, you could potentially change their behavior.

 

Such a technology would be of great practical value, particularly by helping war veterans with traumatic memories and people with anxiety disorders by helping eliminate bad memories that could affect their daily lives.

 

A team from the Massachussetts Institute of Technology (MIT) has found that they can do just that—at a genetic level, no less.



The Tet1 gene

 

The MIT researchers discovered that a particular gene, Tet1, can weaken the fear memory, Discovery News reported.

 

“We learned from this that the animals defective in the Tet1 gene are not capable of weakening the fear memory,” said Le-Huei Tsai, director of MIT's Picower Institute for Learning and Memory.

 

“The results support the notion that once a fear memory is formed, to extinguish that memory a new memory has to form. The new memory competes with the old memory and eventually supersedes the old memory,” Tsai added.

 

She said this could mean potentially treating anxiety disorders at the molecular and cellular levels, inside the brain.

 

“We can now see the bio-chemical cascade of events in the process of memory formation and memory extinction. Hopefully this can lead to new drug discoveries,” she said.

 

In the study, the team put mice in a cage that electrically shocked them. Those with normal Tet1 levels no longer feared the cage once new memories were formed without the shock.

 

But those without the gene still feared the cage even if it no longer shocked them.

 

Forming new memories

“For more than a half century it has been documented that gene expression and protein synthesis are essential for learning and forming new memories. In this study we speculated that the Tet1 gene regulates chemical modifications to DNA,” Tsai added.

 

The researchers learned Tet1 changes levels of DNA methylation, a chemical reaction that allows the formation of new memories. If the reaction is weak, forming new memories is not as efficient.

 

Jelena Radulovic, a professor of bipolar disease at Northwestern University, said this could present a new mechanism of memory regulation and behavior regulation.

 

"Now the question will be whether there will be patterns that emerge, whether there will be side effects on moods and emotions and other aspects. But the findings have real relevance," Radulovic said.

 

She added the results could mean interference with the Tet1 gene and modification of DNA "could be an important target to reduce fear in people with anxiety disorders.”

 

Memory extinction research

 

Meanwhile, Tsai said research in memory extinction is progressing quickly via traditional experimentation and advances in technology.

 

Parallel research focuses on physiological processes that cause memories, rather than turning genes on or off, Discovery News added.

 

It noted researchers at the Scripps Research Institute are studying what causes a drug addict to relapse when confronted with familiar triggers that a person associates with drug use.

 

“Substance users who are trying to stay clean, when exposed to the environment where they used the drug have all kinds of associations and memories in their minds that are strong enough to elicit cravings,” said Courtney Miller, an assistant professor at the Scripps Research Institute, who led the research.

Selective memory disruption
 

Miller said the idea is to "try to selectively disrupt the dangerous memories but not lose other memories.”

 

Gary Lynch, professor of psychiatry and human behavior at University of California School of Medicine, said the study may point to "a completely new strategy for treatment of addiction."

 

"For the past 10 years there have been many challenges to the notion that memories are cemented in. But this study shows that memory really is still a dynamic, malleable business and that there can be another way of dealing with dependency,” Lynch said.

 

Treatment of addiction

In the future, Miller said the process can be generalized to other addictions, such as nicotine.

 

Meanwhile, Tsai said further research may lead to discovering how good and bad memories form.

 

"My prediction is that progress on memory research, including memory extinction, will speed up considerably because of the emerging technology,” she said.

 

She said that technology includes a new 3-D, high-resolution brain imaging called CLARITY, developed by a research team at Stanford University.

 

It lets researchers view the brain in a transparent way, allowing them to see in detail its fine wiring and essential features. — TJD, GMA News